1. Field of the Invention
The present invention relates to a superimposing indicator in which photographing information is superimposed and indicated on an object image within a viewfinder in a single reflex camera.
2. Description of the Related Art
A conventional superimposing indicator within a viewfinder of a single reflex camera is disclosed in U.S. Pat. No. 5,488,446. FIGS. 1 and 2 show an optical system mounted in a single reflex camera, disclosed in the above mentioned publication, where FIG. 2 shows a development of the optical system. Regarding the indicator within the viewfinder, as shown in these drawings, a photographing information projector 50 is disposed close to a tip portion of a quick return mirror 40, which is set in an inclined condition. The photographing information projector 50 has a light emitting diode 51, an information chart 52, which is in front of and illuminated by the light emitting diode 51, and a projecting lens 53 which is disposed in front of the information chart 52. An image indicating photographing information, i.e. a character or the like, is formed in the information chart 52, so that the image of the photographing information is formed on a focusing glass 41, disposed adjacent to the quick return mirror 40, as light is radiated by the emitting diode 51. This photographing information, which is superimposed on an object image obtained through a photographing optical system 43, can be viewed through an eyepiece 42 included in the viewfinder.
Thus, the conventional photographing information projector 50 is disposed so as to be offset with respect to an edge portion of the focusing glass 41, and thus, the projection path of the photographing information does not interfere with the quick return mirror 40. Namely, a bundle of rays K1, passing through the photographing optical system 43, and a bundle of rays K2, radiated from the photographing information projector 50, are made incident on the focusing glass 41 at different angles from each other.
The focusing glass 41 is provided with a Fresnel lens, so that a major portion of the bundle of rays K1, directed from the photographing optical system 43, is directed to the eyepiece 42. However, the bundle of rays directed from the photographing information projector 50 to the eyepiece 42 is very small. Therefore, in the viewfinder, the indication of the photographing information tends to be dark, hindering viewing of the photographing information at various positions of the eye E of the photographer relative to the eyepiece 42.